The present invention relates generally to automatic in vivo de-termination of acidity measures in body fluids. More particularly the invention relates to a bolus according to the preamble of claim 1 and a method according to the preamble of claim 9. The invention also relates to a computer program according to claim 12 and a computer readable medium according to claim 13.
To accomplish an efficient and animal friendly livestock handling it is important to monitor the animals' physiological state and health condition. Of course, to this aim, regular farmer's inspections and veterinary examinations can never be excluded. However, as a complement thereto and to provide an ongoing supervision, various automatic systems can be employed. One example of such a solution involves introducing a so-called bolus into the animal's stomach. More precisely, the bolus should preferably be placed in the reticulum, and normally the bolus has a weight of around 50-200 grams in order not to be forwarded through the digestive system. Once installed in the animal, the bolus may register various health-related parameters of the animal and report corresponding data to an external station via a radio interface.
U.S. Pat. No. 6,059,733 discloses a method of determining a physiological state of a ruminant animal using an ingestible bolus. The bolus includes a temperature sensor and a transmitter. Thus, core body temperatures within the animal's stomach can be registered and reported to a remote receiver for mathematical analysis. As a result, the physiological state of the animal can be determined.
US 2007/0088194 describes a bolus for introducing into a ruminant animal's reticulum. The bolus contains an acoustic sensor for receiving acoustic signals emanated by various signal sources in the animal, such as the heart and respiratory organs, and output values indicative of the animal's health condition.
US 2010/0045309 reveals a fluid sensor for use within the gastro-intestinal tract of a human being. The sensor includes a sensing coil which is immersible in the sample fluid of the gastro-intestinal tract; a signal generator in electrical with the sensing coil for applying an electrical current pulse to the sensing coil; a signal receiver in communication with the sensing coil for measuring an electrical reflection relative to said electrical current pulse; and a data processor for receiving the electrical reflection and for calculating data representative of at least one property, such as pH of the sample fluid based on the electrical reflection. The fluid sensor can also include a reference coil for calibrating the sensing coil. The sensor coil and reference coil can be encapsulated in a swallowable pill shell. Thus, as such, an acidity sensor is known, which operates based on electromagnetic field influencing.